Commit message: vhost: support inflight info sharing

This patch introduces two new messages VHOST_USER_GET_INFLIGHT_FD
and VHOST_USER_SET_INFLIGHT_FD to support transferring a shared
buffer between qemu and backend.

Signed-off-by: Lin Li <lilin24@baidu.com>
Signed-off-by: Xun Ni <nixun@baidu.com>
Signed-off-by: Yu Zhang <zhangyu31@baidu.com>
Signed-off-by: Jin Yu <jin.yu@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
CVE: CVE-2020-10726
CWE: CWE-190
Vulnerability description: A vulnerability was found in DPDK versions 19.11 and above. A malicious container that has direct access to the vhost-user socket can keep sending VHOST_USER_GET_INFLIGHT_FD messages, causing a resource leak (file descriptors and virtual memory), which may result in a denial of service.

Project: dpdk
File: vhost_user.c

vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
			int main_fd)
{
	struct virtio_net *dev = *pdev;
	struct VhostUserMemory *memory = &msg->payload.memory;
	struct rte_vhost_mem_region *reg;
	void *mmap_addr;
	uint64_t mmap_size;
	uint64_t mmap_offset;
	uint64_t alignment;
	uint32_t i;
	int populate;
	int fd;

	if (memory->nregions > VHOST_MEMORY_MAX_NREGIONS) {
		RTE_LOG(ERR, VHOST_CONFIG,
			"too many memory regions (%u)\n", memory->nregions);
		return RTE_VHOST_MSG_RESULT_ERR;
	}

	if (dev->mem && !vhost_memory_changed(memory, dev->mem)) {
		RTE_LOG(INFO, VHOST_CONFIG,
			"(%d) memory regions not changed\n", dev->vid);

		for (i = 0; i < memory->nregions; i++)
			close(msg->fds[i]);

		return RTE_VHOST_MSG_RESULT_OK;
	}

	if (dev->mem) {
		free_mem_region(dev);
		rte_free(dev->mem);
		dev->mem = NULL;
	}

	/* Flush IOTLB cache as previous HVAs are now invalid */
	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
		for (i = 0; i < dev->nr_vring; i++)
			vhost_user_iotlb_flush_all(dev->virtqueue[i]);

	dev->nr_guest_pages = 0;
	if (!dev->guest_pages) {
		dev->max_guest_pages = 8;
		dev->guest_pages = malloc(dev->max_guest_pages *
						sizeof(struct guest_page));
		if (dev->guest_pages == NULL) {
			RTE_LOG(ERR, VHOST_CONFIG,
				"(%d) failed to allocate memory "
				"for dev->guest_pages\n",
				dev->vid);
			return RTE_VHOST_MSG_RESULT_ERR;
		}
	}

	dev->mem = rte_zmalloc("vhost-mem-table", sizeof(struct rte_vhost_memory) +
		sizeof(struct rte_vhost_mem_region) * memory->nregions, 0);
	if (dev->mem == NULL) {
		RTE_LOG(ERR, VHOST_CONFIG,
			"(%d) failed to allocate memory for dev->mem\n",
			dev->vid);
		return RTE_VHOST_MSG_RESULT_ERR;
	}
	dev->mem->nregions = memory->nregions;

	for (i = 0; i < memory->nregions; i++) {
		fd  = msg->fds[i];
		reg = &dev->mem->regions[i];

		reg->guest_phys_addr = memory->regions[i].guest_phys_addr;
		reg->guest_user_addr = memory->regions[i].userspace_addr;
		reg->size            = memory->regions[i].memory_size;
		reg->fd              = fd;

		mmap_offset = memory->regions[i].mmap_offset;

		/* Check for memory_size + mmap_offset overflow */
		if (mmap_offset >= -reg->size) {
			RTE_LOG(ERR, VHOST_CONFIG,
				"mmap_offset (%#"PRIx64") and memory_size "
				"(%#"PRIx64") overflow\n",
				mmap_offset, reg->size);
			goto err_mmap;
		}

		mmap_size = reg->size + mmap_offset;

		/* mmap() without flag of MAP_ANONYMOUS, should be called
		 * with length argument aligned with hugepagesz at older
		 * longterm version Linux, like 2.6.32 and 3.2.72, or
		 * mmap() will fail with EINVAL.
		 *
		 * to avoid failure, make sure in caller to keep length
		 * aligned.
		 */
		alignment = get_blk_size(fd);
		if (alignment == (uint64_t)-1) {
			RTE_LOG(ERR, VHOST_CONFIG,
				"couldn't get hugepage size through fstat\n");
			goto err_mmap;
		}
		mmap_size = RTE_ALIGN_CEIL(mmap_size, alignment);

		populate = (dev->dequeue_zero_copy) ? MAP_POPULATE : 0;
		mmap_addr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
				 MAP_SHARED | populate, fd, 0);

		if (mmap_addr == MAP_FAILED) {
			RTE_LOG(ERR, VHOST_CONFIG,
				"mmap region %u failed.\n", i);
			goto err_mmap;
		}

		reg->mmap_addr = mmap_addr;
		reg->mmap_size = mmap_size;
		reg->host_user_addr = (uint64_t)(uintptr_t)mmap_addr +
				      mmap_offset;

		if (dev->dequeue_zero_copy)
			if (add_guest_pages(dev, reg, alignment) < 0) {
				RTE_LOG(ERR, VHOST_CONFIG,
					"adding guest pages to region %u failed.\n",
					i);
				goto err_mmap;
			}

		RTE_LOG(INFO, VHOST_CONFIG,
			"guest memory region %u, size: 0x%" PRIx64 "\n"
			"\t guest physical addr: 0x%" PRIx64 "\n"
			"\t guest virtual  addr: 0x%" PRIx64 "\n"
			"\t host  virtual  addr: 0x%" PRIx64 "\n"
			"\t mmap addr : 0x%" PRIx64 "\n"
			"\t mmap size : 0x%" PRIx64 "\n"
			"\t mmap align: 0x%" PRIx64 "\n"
			"\t mmap off  : 0x%" PRIx64 "\n",
			i, reg->size,
			reg->guest_phys_addr,
			reg->guest_user_addr,
			reg->host_user_addr,
			(uint64_t)(uintptr_t)mmap_addr,
			mmap_size,
			alignment,
			mmap_offset);

		if (dev->postcopy_listening) {
			/*
			 * We haven't a better way right now than sharing
			 * DPDK's virtual address with Qemu, so that Qemu can
			 * retrieve the region offset when handling userfaults.
			 */
			memory->regions[i].userspace_addr =
				reg->host_user_addr;
		}
	}
	if (dev->postcopy_listening) {
		/* Send the addresses back to qemu */
		msg->fd_num = 0;
		send_vhost_reply(main_fd, msg);

		/* Wait for qemu to acknolwedge it's got the addresses
		 * we've got to wait before we're allowed to generate faults.
		 */
		VhostUserMsg ack_msg;
		if (read_vhost_message(main_fd, &ack_msg) <= 0) {
			RTE_LOG(ERR, VHOST_CONFIG,
				"Failed to read qemu ack on postcopy set-mem-table\n");
			goto err_mmap;
		}
		if (ack_msg.request.master != VHOST_USER_SET_MEM_TABLE) {
			RTE_LOG(ERR, VHOST_CONFIG,
				"Bad qemu ack on postcopy set-mem-table (%d)\n",
				ack_msg.request.master);
			goto err_mmap;
		}

		/* Now userfault register and we can use the memory */
		for (i = 0; i < memory->nregions; i++) {
#ifdef RTE_LIBRTE_VHOST_POSTCOPY
			reg = &dev->mem->regions[i];
			struct uffdio_register reg_struct;

			/*
			 * Let's register all the mmap'ed area to ensure
			 * alignment on page boundary.
			 */
			reg_struct.range.start =
				(uint64_t)(uintptr_t)reg->mmap_addr;
			reg_struct.range.len = reg->mmap_size;
			reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;

			if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER,
						&reg_struct)) {
				RTE_LOG(ERR, VHOST_CONFIG,
					"Failed to register ufd for region %d: (ufd = %d) %s\n",
					i, dev->postcopy_ufd,
					strerror(errno));
				goto err_mmap;
			}
			RTE_LOG(INFO, VHOST_CONFIG,
				"\t userfaultfd registered for range : %llx - %llx\n",
				reg_struct.range.start,
				reg_struct.range.start +
				reg_struct.range.len - 1);
#else
			goto err_mmap;
#endif
		}
	}

	for (i = 0; i < dev->nr_vring; i++) {
		struct vhost_virtqueue *vq = dev->virtqueue[i];

		if (vq->desc || vq->avail || vq->used) {
			/*
			 * If the memory table got updated, the ring addresses
			 * need to be translated again as virtual addresses have
			 * changed.
			 */
			vring_invalidate(dev, vq);

			dev = translate_ring_addresses(dev, i);
			if (!dev) {
				dev = *pdev;
				goto err_mmap;
			}

			*pdev = dev;
		}
	}

	dump_guest_pages(dev);

	return RTE_VHOST_MSG_RESULT_OK;

err_mmap:
	free_mem_region(dev);
	rte_free(dev->mem);
	dev->mem = NULL;
	return RTE_VHOST_MSG_RESULT_ERR;
}

Project: dpdk
File: vhost_user.c

vhost_user_set_features(struct virtio_net **pdev, struct VhostUserMsg *msg,
			int main_fd __rte_unused)
{
	struct virtio_net *dev = *pdev;
	uint64_t features = msg->payload.u64;
	uint64_t vhost_features = 0;
	struct rte_vdpa_device *vdpa_dev;
	int did = -1;

	rte_vhost_driver_get_features(dev->ifname, &vhost_features);
	if (features & ~vhost_features) {
		RTE_LOG(ERR, VHOST_CONFIG,
			"(%d) received invalid negotiated features.\n",
			dev->vid);
		return RTE_VHOST_MSG_RESULT_ERR;
	}

	if (dev->flags & VIRTIO_DEV_RUNNING) {
		if (dev->features == features)
			return RTE_VHOST_MSG_RESULT_OK;

		/*
		 * Error out if master tries to change features while device is
		 * in running state. The exception being VHOST_F_LOG_ALL, which
		 * is enabled when the live-migration starts.
		 */
		if ((dev->features ^ features) & ~(1ULL << VHOST_F_LOG_ALL)) {
			RTE_LOG(ERR, VHOST_CONFIG,
				"(%d) features changed while device is running.\n",
				dev->vid);
			return RTE_VHOST_MSG_RESULT_ERR;
		}

		if (dev->notify_ops->features_changed)
			dev->notify_ops->features_changed(dev->vid, features);
	}

	dev->features = features;
	if (dev->features &
		((1 << VIRTIO_NET_F_MRG_RXBUF) | (1ULL << VIRTIO_F_VERSION_1))) {
		dev->vhost_hlen = sizeof(struct virtio_net_hdr_mrg_rxbuf);
	} else {
		dev->vhost_hlen = sizeof(struct virtio_net_hdr);
	}
	RTE_LOG(INFO, VHOST_CONFIG,
		"negotiated Virtio features: 0x%" PRIx64 "\n", dev->features);
	VHOST_LOG_DEBUG(VHOST_CONFIG,
		"(%d) mergeable RX buffers %s, virtio 1 %s\n",
		dev->vid,
		(dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ? "on" : "off",
		(dev->features & (1ULL << VIRTIO_F_VERSION_1)) ? "on" : "off");

	if ((dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET) &&
	    !(dev->features & (1ULL << VIRTIO_NET_F_MQ))) {
		/*
		 * Remove all but first queue pair if MQ hasn't been
		 * negotiated. This is safe because the device is not
		 * running at this stage.
		 */
		while (dev->nr_vring > 2) {
			struct vhost_virtqueue *vq;

			vq = dev->virtqueue[--dev->nr_vring];
			if (!vq)
				continue;

			dev->virtqueue[dev->nr_vring] = NULL;
			cleanup_vq(vq, 1);
			free_vq(dev, vq);
		}
	}

	did = dev->vdpa_dev_id;
	vdpa_dev = rte_vdpa_get_device(did);
	if (vdpa_dev && vdpa_dev->ops->set_features)
		vdpa_dev->ops->set_features(dev->vid);

	return RTE_VHOST_MSG_RESULT_OK;
}

Project: dpdk
File: vhost_user.c

vhost_user_set_vring_num(struct virtio_net **pdev,
			struct VhostUserMsg *msg,
			int main_fd __rte_unused)
{
	struct virtio_net *dev = *pdev;
	struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];

	vq->size = msg->payload.state.num;

	/* VIRTIO 1.0, 2.4 Virtqueues says:
	 *
	 *   Queue Size value is always a power of 2. The maximum Queue Size
	 *   value is 32768.
	 */
	if ((vq->size & (vq->size - 1)) || vq->size > 32768) {
		RTE_LOG(ERR, VHOST_CONFIG,
			"invalid virtqueue size %u\n", vq->size);
		return RTE_VHOST_MSG_RESULT_ERR;
	}

	if (dev->dequeue_zero_copy) {
		vq->nr_zmbuf = 0;
		vq->last_zmbuf_idx = 0;
		vq->zmbuf_size = vq->size;
		vq->zmbufs = rte_zmalloc(NULL, vq->zmbuf_size *
					 sizeof(struct zcopy_mbuf), 0);
		if (vq->zmbufs == NULL) {
			RTE_LOG(WARNING, VHOST_CONFIG,
				"failed to allocate mem for zero copy; "
				"zero copy is force disabled\n");
			dev->dequeue_zero_copy = 0;
		}
		TAILQ_INIT(&vq->zmbuf_list);
	}

	if (vq_is_packed(dev)) {
		vq->shadow_used_packed = rte_malloc(NULL,
				vq->size *
				sizeof(struct vring_used_elem_packed),
				RTE_CACHE_LINE_SIZE);
		if (!vq->shadow_used_packed) {
			RTE_LOG(ERR, VHOST_CONFIG,
					"failed to allocate memory for shadow used ring.\n");
			return RTE_VHOST_MSG_RESULT_ERR;
		}

	} else {
		vq->shadow_used_split = rte_malloc(NULL,
				vq->size * sizeof(struct vring_used_elem),
				RTE_CACHE_LINE_SIZE);
		if (!vq->shadow_used_split) {
			RTE_LOG(ERR, VHOST_CONFIG,
					"failed to allocate memory for shadow used ring.\n");
			return RTE_VHOST_MSG_RESULT_ERR;
		}
	}

	vq->batch_copy_elems = rte_malloc(NULL,
				vq->size * sizeof(struct batch_copy_elem),
				RTE_CACHE_LINE_SIZE);
	if (!vq->batch_copy_elems) {
		RTE_LOG(ERR, VHOST_CONFIG,
			"failed to allocate memory for batching copy.\n");
		return RTE_VHOST_MSG_RESULT_ERR;
	}

	return RTE_VHOST_MSG_RESULT_OK;
}

Project: dpdk
File: vhost_user.c

vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg,
			int main_fd __rte_unused)
{
	struct virtio_net *dev = *pdev;
	struct vhost_vring_file file;
	struct vhost_virtqueue *vq;

	file.index = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
	if (msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
		file.fd = VIRTIO_INVALID_EVENTFD;
	else
		file.fd = msg->fds[0];
	RTE_LOG(INFO, VHOST_CONFIG,
		"vring kick idx:%d file:%d\n", file.index, file.fd);

	/* Interpret ring addresses only when ring is started. */
	dev = translate_ring_addresses(dev, file.index);
	if (!dev)
		return RTE_VHOST_MSG_RESULT_ERR;

	*pdev = dev;

	vq = dev->virtqueue[file.index];

	/*
	 * When VHOST_USER_F_PROTOCOL_FEATURES is not negotiated,
	 * the ring starts already enabled. Otherwise, it is enabled via
	 * the SET_VRING_ENABLE message.
	 */
	if (!(dev->features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) {
		vq->enabled = 1;
		if (dev->notify_ops->vring_state_changed)
			dev->notify_ops->vring_state_changed(
				dev->vid, file.index, 1);
	}

	if (vq->kickfd >= 0)
		close(vq->kickfd);
	vq->kickfd = file.fd;

	return RTE_VHOST_MSG_RESULT_OK;
}

Project: dpdk
File: vhost_user.c

translate_ring_addresses(struct virtio_net *dev, int vq_index)
{
	struct vhost_virtqueue *vq = dev->virtqueue[vq_index];
	struct vhost_vring_addr *addr = &vq->ring_addrs;
	uint64_t len, expected_len;

	if (vq_is_packed(dev)) {
		len = sizeof(struct vring_packed_desc) * vq->size;
		vq->desc_packed = (struct vring_packed_desc *)(uintptr_t)
			ring_addr_to_vva(dev, vq, addr->desc_user_addr, &len);
		vq->log_guest_addr = 0;
		if (vq->desc_packed == NULL ||
				len != sizeof(struct vring_packed_desc) *
				vq->size) {
			RTE_LOG(DEBUG, VHOST_CONFIG,
				"(%d) failed to map desc_packed ring.\n",
				dev->vid);
			return dev;
		}

		dev = numa_realloc(dev, vq_index);
		vq = dev->virtqueue[vq_index];
		addr = &vq->ring_addrs;

		len = sizeof(struct vring_packed_desc_event);
		vq->driver_event = (struct vring_packed_desc_event *)
					(uintptr_t)ring_addr_to_vva(dev,
					vq, addr->avail_user_addr, &len);
		if (vq->driver_event == NULL ||
				len != sizeof(struct vring_packed_desc_event)) {
			RTE_LOG(DEBUG, VHOST_CONFIG,
				"(%d) failed to find driver area address.\n",
				dev->vid);
			return dev;
		}

		len = sizeof(struct vring_packed_desc_event);
		vq->device_event = (struct vring_packed_desc_event *)
					(uintptr_t)ring_addr_to_vva(dev,
					vq, addr->used_user_addr, &len);
		if (vq->device_event == NULL ||
				len != sizeof(struct vring_packed_desc_event)) {
			RTE_LOG(DEBUG, VHOST_CONFIG,
				"(%d) failed to find device area address.\n",
				dev->vid);
			return dev;
		}

		vq->access_ok = 1;
		return dev;
	}

	/* The addresses are converted from QEMU virtual to Vhost virtual. */
	if (vq->desc && vq->avail && vq->used)
		return dev;

	len = sizeof(struct vring_desc) * vq->size;
	vq->desc = (struct vring_desc *)(uintptr_t)ring_addr_to_vva(dev,
			vq, addr->desc_user_addr, &len);
	if (vq->desc == 0 || len != sizeof(struct vring_desc) * vq->size) {
		RTE_LOG(DEBUG, VHOST_CONFIG,
			"(%d) failed to map desc ring.\n",
			dev->vid);
		return dev;
	}

	dev = numa_realloc(dev, vq_index);
	vq = dev->virtqueue[vq_index];
	addr = &vq->ring_addrs;

	len = sizeof(struct vring_avail) + sizeof(uint16_t) * vq->size;
	if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))
		len += sizeof(uint16_t);
	expected_len = len;
	vq->avail = (struct vring_avail *)(uintptr_t)ring_addr_to_vva(dev,
			vq, addr->avail_user_addr, &len);
	if (vq->avail == 0 || len != expected_len) {
		RTE_LOG(DEBUG, VHOST_CONFIG,
			"(%d) failed to map avail ring.\n",
			dev->vid);
		return dev;
	}

	len = sizeof(struct vring_used) +
		sizeof(struct vring_used_elem) * vq->size;
	if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))
		len += sizeof(uint16_t);
	expected_len = len;
	vq->used = (struct vring_used *)(uintptr_t)ring_addr_to_vva(dev,
			vq, addr->used_user_addr, &len);
	if (vq->used == 0 || len != expected_len) {
		RTE_LOG(DEBUG, VHOST_CONFIG,
			"(%d) failed to map used ring.\n",
			dev->vid);
		return dev;
	}

	if (vq->last_used_idx != vq->used->idx) {
		RTE_LOG(WARNING, VHOST_CONFIG,
			"last_used_idx (%u) and vq->used->idx (%u) mismatches; "
			"some packets maybe resent for Tx and dropped for Rx\n",
			vq->last_used_idx, vq->used->idx);
		vq->last_used_idx  = vq->used->idx;
		vq->last_avail_idx = vq->used->idx;
	}

	vq->log_guest_addr =
		translate_log_addr(dev, vq, addr->log_guest_addr);
	if (vq->log_guest_addr == 0) {
		RTE_LOG(DEBUG, VHOST_CONFIG,
			"(%d) failed to map log_guest_addr .\n",
			dev->vid);
		return dev;
	}
	vq->access_ok = 1;

	VHOST_LOG_DEBUG(VHOST_CONFIG, "(%d) mapped address desc: %p\n",
			dev->vid, vq->desc);
	VHOST_LOG_DEBUG(VHOST_CONFIG, "(%d) mapped address avail: %p\n",
			dev->vid, vq->avail);
	VHOST_LOG_DEBUG(VHOST_CONFIG, "(%d) mapped address used: %p\n",
			dev->vid, vq->used);
	VHOST_LOG_DEBUG(VHOST_CONFIG, "(%d) log_guest_addr: %" PRIx64 "\n",
			dev->vid, vq->log_guest_addr);

	return dev;
}

Project: dpdk
File: vhost_user.c

vhost_user_set_inflight_fd(struct virtio_net **pdev, VhostUserMsg *msg,
			   int main_fd __rte_unused)
{
	uint64_t mmap_size, mmap_offset;
	uint16_t num_queues, queue_size;
	uint32_t pervq_inflight_size;
	struct virtio_net *dev = *pdev;
	void *addr;
	int fd;

	fd = msg->fds[0];
	if (msg->size != sizeof(msg->payload.inflight) || fd < 0) {
		RTE_LOG(ERR, VHOST_CONFIG,
			"invalid set_inflight_fd message size is %d,fd is %d\n",
			msg->size, fd);
		return RTE_VHOST_MSG_RESULT_ERR;
	}

	mmap_size = msg->payload.inflight.mmap_size;
	mmap_offset = msg->payload.inflight.mmap_offset;
	num_queues = msg->payload.inflight.num_queues;
	queue_size = msg->payload.inflight.queue_size;

	if (vq_is_packed(dev))
		pervq_inflight_size = get_pervq_shm_size_packed(queue_size);
	else
		pervq_inflight_size = get_pervq_shm_size_split(queue_size);

	RTE_LOG(INFO, VHOST_CONFIG,
		"set_inflight_fd mmap_size: %"PRIu64"\n", mmap_size);
	RTE_LOG(INFO, VHOST_CONFIG,
		"set_inflight_fd mmap_offset: %"PRIu64"\n", mmap_offset);
	RTE_LOG(INFO, VHOST_CONFIG,
		"set_inflight_fd num_queues: %u\n", num_queues);
	RTE_LOG(INFO, VHOST_CONFIG,
		"set_inflight_fd queue_size: %u\n", queue_size);
	RTE_LOG(INFO, VHOST_CONFIG,
		"set_inflight_fd fd: %d\n", fd);
	RTE_LOG(INFO, VHOST_CONFIG,
		"set_inflight_fd pervq_inflight_size: %d\n",
		pervq_inflight_size);

	if (!dev->inflight_info) {
		dev->inflight_info = calloc(1,
					    sizeof(struct inflight_mem_info));
		if (dev->inflight_info == NULL) {
			RTE_LOG(ERR, VHOST_CONFIG,
				"failed to alloc dev inflight area\n");
			return RTE_VHOST_MSG_RESULT_ERR;
		}
	}

	if (dev->inflight_info->addr)
		munmap(dev->inflight_info->addr, dev->inflight_info->size);

	addr = mmap(0, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED,
		    fd, mmap_offset);
	if (addr == MAP_FAILED) {
		RTE_LOG(ERR, VHOST_CONFIG, "failed to mmap share memory.\n");
		return RTE_VHOST_MSG_RESULT_ERR;
	}

	if (dev->inflight_info->fd)
		close(dev->inflight_info->fd);

	dev->inflight_info->fd = fd;
	dev->inflight_info->addr = addr;
	dev->inflight_info->size = mmap_size;

	return RTE_VHOST_MSG_RESULT_OK;
}